Devices which automatically project balls to assist in the practice and teaching of sports participants are known in the art. For example, numerous types of baseball or tennis ball propelling machines exist so that the athlete can practice by himself to enhance his skills. Likewise, devices exist which can serve or set balls, such as volleyballs, so that the volleyball enthusiast can practice the skill, for example, of spiking the ball across the net.
While such volleyball propelling devices are adequate for their intended uses, such are not without their problems. Many such devices are overly heavy for their purposes requiring a large motor or power device to propel the balls through a range of distances and are thus quite inefficient. Moreover, most of these devices utilize a hopper-like ball feeding mechanism which can result in misfeeding or a clogging of the feeding of the balls to the discharge area. For those devices which have the ability to adjust the trajectory of the propelled ball, some utilize a cumbersome discharge chute to establish the trajectory. The friction generated by such chutes, as the balls pass therethrough, necessitates more input power, even for shorter projection distances, thereby compounding the inefficiency problem. Finally, not all of the known devices provide complete adjustability in, for example, propulsion force, trajectory or the like, and thus they limit the user to specific practice drills.